There is a rapidly growing trend toward mobile and remote data access over high-speed communication networks, such as provided by 3G or 4G cellular services. For example, using these services, users now rely on their smartphones for texting, access to email, banking, and social media, and for sending and receiving pictures and video.
Typically, wireless network performance depends in part on the quality of the transmission channel. For example, if the channel conditions are good, the network may perform with higher speed and capacity than when the channel conditions are poor. To obtain the best network performance, wireless networks may rely on user devices (e.g., user equipment “UE”) to report control information back to the network. The control information includes parameters indicating the channel conditions and/or transmission parameters. One way user devices report control information back to the network is through a physical uplink shared channel (PUSCH). The network receives the control information over this shared channel and uses the received parameters to adjust data transmissions for optimum performance based on the network conditions indicated by the received parameters.
Acknowledgement information is also transmitted through the PUSCH. For example, after a user device receives a transmission from a network server, it generates an acknowledgement (ACK) that indicates whether or not the transmission was properly received. The ACK is then transmitted back to the network server through the PUSCH. The server can determine from the received ACK whether the transmission was properly received, and initiate a retransmission if necessary. In a time division duplex (TDD) communication system, the user device generates encoded ACK blocks that are scrambled with a scrambling sequence before transmission over the PUSCH for a TDD ACK bundling scenario. Typically, the scrambling sequence for TDD ACK bundling is selected from four or more possible scrambling sequences.
When the ACK information on the PUSCH is received at the network server, it is processed to obtain the actual ACK values. For example, the processing may include descrambling, soft-combining, and decoding of the received ACK information. In order to do this, conventional systems first determine the correct scrambling sequence for TDD ACK bundling that was used to scramble the ACK information. Once the exact scrambling sequence is determined, the process to recover the ACK information can be performed using that scrambling sequence to descramble the received information.
However, in conventional systems, additional parameters may need to be acquired and/or data processing may need to be performed before the exact scrambling sequence can be determined. Thus, conventional systems have to wait to perform these additional functions to determine the exact scrambling sequence before performing the operations needed to recover the ACK information, which may result in reduced network performance.
Therefore, it is desirable to have a mechanism that efficiently recovers received acknowledgement information and overcomes the problems associated with conventional systems.